AS3910-BQFT austriamicrosystems, AS3910-BQFT Datasheet - Page 19

• Manufacturer Part Number: AS3910-BQFT
• Description: IC RFID READER SPI 32-QFN
• Manufacturer: austriamicrosystems

Specifications of AS3910-BQFT

• Rf Type: Read / Write
• Frequency: 13.56MHz
• Features: ISO14443A, ISO1443B
• Package / Case: 32-VFQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: AS3910-BQFTTR

AS3910
Data Sheet - A p p l i c a t i o n I n f o r m a t i o n
8.9.5 Sending Direct Commands
Direct commands have no arguments, so a single byte is sent. Command mode is entered if the SPI is started with two leading ONE. After the
COMMAND mode code 11
During the direct command execution, starting another activity over the SPI interface is not allowed.
Figure 8. Sending Direct Commands
8.9.6 Loading Transmitting Data into FIFO
Loading the transmitting data into the FIFO is similar to writing data into an addressable registers. Difference is that in case of loading more bytes
all bytes go to the FIFO. The command mode code 10 indicates FIFO operations. In case of loading transmitting data into FIFO all bits <C5 –
C0> are set to 0. Then a bit-stream, the data to be sent (1 to 32 bytes), can be transferred. In case the command is terminated by putting SEN
low before a packet of 8 bits composing one byte is sent, writing of that particular byte in FIFO is not performed.
Transmitting Data into the FIFO.
Figure 9. Loading Transmitting Data into FIFO
8.9.7 Reading Received Data from FIFO
Reading received data from the FIFO is similar to reading data from an addressable registers. Difference is that in case of reading more bytes
they all come from the FIFO. The command mode code 10 indicates FIFO operations. In case of reading the received data from the FIFO all bits
<C5 – C0> are set to 1. On the following SCLK rising edges the data from FIFO appears as in case of read data from addressable registers. In
case the command is terminated by putting SEN low before a packet of 8 bits composing one byte is read that particular byte is considered
unread and will be the first one read in next FIFO read operation.
8.9.8 Interrupt Interface
When an interrupt condition is met the source of interrupt bit is set in the Interrupt Register and the INTR pin transitions to high.
The microcontroller then reads the Interrupt Register to distinguish between different interrupt sources. After the Interrupt Register is read its
content is reset to 0 and INTR pin signal transitions to low.
Note: There may be more then one Interrupt Register bit set in case the microcontroller did not immediately read the Interrupt Register after
www.austriamicrosystems.com/HF_RFID_Reader/AS3910
SDATAI
SCLK
SEN
the INTR signal was set and another event causing interrupt occurred.
SDATAI
X
SCLK
SEN
10 pattern
indicates
FIFO mode
1
(see Table
0
X
Two leading
ONE indicate
COMMAND
Mode
0
1
9), the six bit command code is sent MSB to the LSB. The command is executed on falling edge of SEN.
SCLK raising
edge data is
transferred from
µC
0
1
0
C5
0
SCLK
falling edge
Data is sampled
SCLK raising
edge data is
transferred from
µC
0
C4
Revision 2.3
0
Start of
payload
Data
C3
C2
SCLK
falling edge
Data is sampled
C1
1 to 32
bytes
C0
Figure 9
SEN falling edge
signals start of
command execution
X
shows how to load the
SEN falling
edge signals
end of
COMMAND
Mode
X
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